Recombinant DNA technology makes it possible to produce large amounts of desired proteins in host cells. To recover a recombinantly produced protein expressed in a host cell, it is first necessary to lyse the cell and then extract the protein from the cellular components. The lysis method should not be harmful to the native characteristics of the protein of interest.
Sonication, French press and enzymatic lysis, either alone or in combination with detergents, are currently available techniques used for cell lysis and protein isolation from host cells. These techniques, however, either require special instrumentation that may not always be available or have other limitations, such as being time consuming or generating heat which can denature certain proteins. Also, the methods, in general, do not permit the recovery of soluble recombinant protein in high yields.
In addition, the available methods do not allow for the optimum recovery of the protein of interest from precipitated dense, granular protein forms, known as inclusion bodies, that are distributed throughout the cytoplasm of the cell. In the expression of some proteins, the inclusion bodies contain high levels of the protein of interest and they can be easily separated from other cytoplasmic proteins by centrifugation. However, using current techniques, it is difficult to extract and purify the protein of interest from the inclusion bodies.